Quiet motorized window treatment system

ABSTRACT

A motorized window treatment system may include a roller tube, a covering material windingly attached to the roller tube, and a drive assembly that may be at least partially disposed within the roller tube. The drive assembly may include a motor having a drive shaft that is elongate along a longitudinal direction and a drive gear attached to the drive shaft such that a toothed portion of the drive gear is cantilevered with respect to the drive shaft. The drive assembly may include a gear assembly having a pair of intermediate gears on opposed sides of the drive gear. Rotation of the drive gear may be transferred through the pair of intermediate gears, a connecting gear, a planetary gear set, a cage, and an idler to the roller tube. Rotation of the roller tube may cause the covering material to move between an open position and a closed position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/461,962, filed Mar. 17, 2017, which is a continuation of U.S. patentapplication Ser. No. 14/490,327, filed Sep. 18, 2014, which issued asU.S. Pat. No. 9,598,901 on Mar. 21, 2017, which claims priority to U.S.provisional patent application No. 61/879,305, filed Sep. 18, 2013, thedisclosures of which are incorporated herein by reference in theirentireties.

BACKGROUND

A motorized window treatment system may include a covering materialwound onto a roller tube. The covering material may include a weightedhembar at a lower end of the covering material, such that the coveringmaterial extends vertically (e.g., hangs) in front of a window.Motorized window treatments may include a drive system that is coupledto the roller tube to provide for tube rotation, such that the lower endof the covering material can be raised and lowered (i.e., moved in avertical direction) by rotating the roller tube. The drive system mayinclude a motor having a drive shaft and a gear train that isoperatively coupled to (e.g., in communication with) the drive shaft androller tube such that actuation of the motor causes the roller tube torotate. The motor may be a direct current (DC) motor powered by a DCpower source or an alternating current (AC) motor powered by an AC powersource.

The torque capability and efficiency of a DC motor may vary depending onthe motor speed. While the particular values of motor speed, torquecapability, and efficiency may vary for different DC motors, certaincharacteristics may be shared by most DC motors. For example, motorspeed and motor torque capability may vary linearly, and inversely,throughout the entire range of motor speeds including very low speedsapproaching zero. Motor efficiency may generally reach peak efficiencyunder light-duty conditions (e.g., relatively low torque capability at amotor speed greater than 50% of maximum motor speed). When a DC motoroperates at a peak efficiency (e.g., at greater speeds), the motor maygenerate undesired noise. Manufactures may operate the motor at a slowerspeed and a lower efficiency, to reduce a noise level of the motor.

SUMMARY

A motorized window treatment system may include a roller tube, acovering material, and a drive assembly. The covering material may bewindingly attached to the roller tube such that rotating the roller tubecauses the covering material to move between a first position and asecond position. The first position and the second position may includeone or more positions between and including an open position and aclosed position.

The drive assembly may be operatively coupled to the roller tube forrotating the roller tube about a longitudinal axis. The drive assemblymay include a motor, a drive gear, and/or a gear assembly. The motor mayinclude a drive shaft that is elongate parallel to a longitudinal axisof the roller tube. The drive shaft may define a drive shaft rotationalaxis. The drive shaft may include an end that is distal from the motor.The drive shaft may define a drive shaft diameter.

The drive gear may be attached to the drive shaft. The drive gear maydefine a rotational axis. The drive gear rotational axis may be in acoaxial relationship with the drive shaft rotational axis. The drivegear may include a toothed portion distal from the end of the driveshaft. The toothed portion of the drive gear may be adapted to rotateabout the drive gear rotational axis. The toothed portion of the drivegear may define a root diameter. The root diameter may be less than thedrive shaft diameter. The toothed portion may be spaced from the driveshaft along the drive shaft rotational axis. The toothed portion mayinclude eight or more and twelve or less gear teeth. The gear teeth maybe helical gear teeth. The toothed portion may be plastic. The drivegear may include a coupling portion. The coupling portion may extendfrom the toothed portion. The coupling portion may mate with the driveshaft to operatively couple the drive gear to the drive shaft. Thecoupling portion may include a non-plastic portion. The non-plasticportion may operatively couple the toothed portion to the couplingportion.

The gear assembly may be operatively coupled to the toothed portion ofthe drive gear and operatively coupled to the roller tube such thatactuation of the motor causes the roller tube to rotate about thelongitudinal axis. The gear assembly may include a pair of intermediategears. The pair of intermediate gears may be disposed on opposed sidesof the toothed portion of the drive gear. The gear assembly may includea planetary gear set. The planetary gear set may be operatively coupledto the roller tube. The gear assembly may include a connecting gear. Theconnecting gear may be operatively coupled to the pair of intermediategears and the planetary gear set.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of an example motorized window treatmentsystem that includes a roller tube and a covering material windinglyattached to the roller tube.

FIG. 1B is an exploded view of the example roller tube shown in FIG. 1A,the motorized window treatment system including a drive assembly atleast partially disposed within the roller tube and configured to rotatethe roller tube so as to cause the covering material to move between aclosed position and an open position.

FIG. 2A is a top perspective view of the example drive assembly shown inFIG. 1B, the drive assembly including a motor, a drive gear coupled tothe motor, and a gear assembly operatively coupled to the drive gear andthe roller tube such that actuation of the motor causes the roller tubeto move the covering material between the open position and the closedposition.

FIG. 2B is a top plan view of the example drive assembly shown in FIG.2A.

FIG. 2C is a detailed view of the example drive gear and gear assemblyof the drive assembly shown in FIG. 2B, the gear assembly including geara pair of intermediate gears disposed on opposed sides of the drivegear, a planetary gear set that is operatively coupled to the rollertube, and a connecting gear that is operatively coupled to the pair ofintermediate gears and the planetary gear set.

FIG. 2D is a cross-section of the example drive gear and the gearassembly shown in FIG. 2C, the drive gear including a toothed portionthat is cantilevered with respect to a drive shaft of the motor and isspaced from the drive shaft of the motor along a longitudinal direction.

FIG. 3 is a cross-section of an example drive gear that includes aplastic toothed portion and a coupling portion having a non-plasticportion and a plastic portion.

DETAILED DESCRIPTION

FIGS. 1A and 1B depict an example motorized window treatment system 10that includes a roller tube 18 and a covering material 22 windinglyattached to the roller tube 18. The motorized window treatment system 10includes a housing 14 (e.g., a pocket or a headrail) that is configuredto be coupled to or otherwise mounted to a structure. For example, thehousing 14 may be configured to be mounted to (e.g., attached to) awindow frame, a wall, or other structure, such that the motorized windowtreatment system 10 is mounted proximate to an opening (e.g., over theopening or in the opening), such as a window for example. The motorizedwindow treatment system 10 may further include a rotational element,such as a roller tube 18 that is elongate along a longitudinal directionL, and that is rotatably mounted (e.g., rotatably supported) within thehousing 14. The longitudinal direction L may be referred to as a firstdirection. The roller tube 18 may define a longitudinal axis 12. Themotorized window treatment system 10 may include a covering material 22that is windingly attached to the roller tube 18, such that rotation ofthe roller tube 18 causes the covering material 22 to wind or unwindfrom the roller tube 18 along a transverse direction T that extendsperpendicular to the longitudinal direction L. The transverse directionT may be referred to as a second direction. For example, rotation of theroller tube 18 may cause the covering material 22 to move between araised (e.g., open) position and a lowered (e.g., closed) position alongthe transverse direction T.

The covering material 22 may include a first end (e.g., a top or upperend) that is coupled to the roller tube 18 and a second end (e.g., abottom or lower end) that is coupled to a hembar 24. The hembar 24 maybe configured, for instance weighted, to cause the covering material 22to hang vertically. Rotation of the roller tube 18 may cause the hembar24 to move toward or away from the housing 14. The housing 14 may bemade of any suitable material, such as plastic or metal. It should beappreciated, however, that the housing 14 may be made from any material,or from any combination of materials. The covering material 22 may beany suitable material, or form any combination of materials. Forexample, the covering material 22 may be “scrim,” woven cloth, non-wovenmaterial, light-control film, screen, and/or mesh. The covering material22 may be any type of shade. For example, the covering material 22 maybe a roller shade as illustrated, a soft sheer shade, a drapery, or acellular shade.

As shown in FIG. 1A, the motorized window treatment system 10 mayinclude a battery compartment 26. The battery compartment 26 may beconfigured to retain a plurality of batteries 28. The batterycompartment 26 may be spaced from the roller tube 18 as illustrated. Thebattery compartment 26 may be disposed within the roller tube 18. Thebatteries 28 may be configured to power a drive assembly, amicroprocessor, and/or any other electrical component of the motorizedwindow treatment system 10. The motorized window treatment system 10 maybe hard wired.

As shown in FIG. 1B, the motorized window treatment system 10 mayinclude a drive assembly 30, a control circuit 31 electrically connectedto the drive assembly 30, a first idler 32 a, and a second idler 32 b.The drive assembly 30, the control circuit 31, the first idler 32 a, andthe second idler 32 b may at least partially be disposed within theroller tube 18. For example, the control circuit 31 may include amicroprocessor and may be mounted to a printed circuit board (PCB). Thedrive assembly 30 and the control circuit 31 may be powered by thebatteries 28. The drive assembly 30 may be coupled to the first idler 32a such that when the drive assembly 30 is actuated, the first idler 32 ais driven by the drive assembly 30 to thereby cause the roller tube 18to rotate. The second idler 32 b may be passive and may rotate as thefirst idler 32 a is driven by the drive assembly 30. The drive assembly30 and control circuit 31 may be configured to allow for control of therotation of the roller tube 18. A user of the motorized window treatmentsystem 10 may control the rotation of the roller tube 18 to move thecovering material 22 to a desired position. The drive assembly 30 mayinclude a sensor that monitors the position of the covering material 22,so that the control circuit 31 knows the position of the coveringmaterial 22 relative to one or more limits (e.g., an upper limit and/ora lower limit) of the covering material 22 at any given time. The driveassembly 30 may be locally controlled (e.g., with a push button) and/orremotely controlled (e.g. wirelessly controlled with an infrared (IR) orradio frequency (RF) remote control device). The control circuit 31 mayinclude an RF transceiver or receiver, and/or an antenna that may beenclosed within the housing 14 or coupled to an exterior portion of thehousing 14. Examples of drive assemblies and control circuits formotorized roller shades are described in greater detail in U.S. Pat. No.6,983,783, issued Jan. 10, 2006, entitled “Motorized Shade ControlSystem.” U.S. Pat. No. 7,723,939, issued May 25, 2010, entitled“Radio-Frequency Controlled Motorized Roller Shade,” and U.S. Pat. No.7,839,109, issued Nov. 23, 2010, entitled “Method Of Controlling AMotorized Window Treatment,” the entire contents of each of which arehereby incorporated herein by reference. It should be appreciated, thatthe drive assembly 30 may be configured to rotate rotational elementsother than a roller tube 18. For example, the drive assembly 30 can beconfigured to rotate a drive shaft that winds up lift cords as disclosedin U.S. Pat. No. 8,950,461, issued Feb. 10, 2015, entitled “MotorizedWindow Treatment,” the entire contents of which is hereby incorporatedherein by reference.

As shown in FIG. 1B, the drive assembly 30 and the control circuit 31may be disposed within a drive housing 200. The drive housing 200 mayinclude a first section 202 and a second section 204. The first section202 and the second section 204 may fit together along a split line 232to house the drive assembly 30 and the control circuit 31. The driveassembly 30 may be supported in the drive housing 200 by one or more ofthe following non-rotating support parts. The drive assembly 30 mayinclude a collar 218 that is disposed between the motor 34 and a gearassembly. The collar 218 may rest in a molded channel of the drivehousing 200. The drive assembly 30 may include one or more disks 212,216 that support the rotating elements of the drive assembly 30 withinthe drive housing 200. The disk 216 may include a plurality of tabs 214that engage a plurality of slots in the drive housing 200. The disk 212may be disposed within one or more channels in the drive housing 200.The drive assembly 30 may include a ring gear 120 with a plurality oftabs 210 that engage a plurality of slots 208 in the drive housing 200.

As shown in FIG. 1B, the first idler 32 a may be connected to a cage 220that engages one or more planetary gears. The cage 220 may be spacedfrom the first idler 32 a such that the drive housing 200 may besupported by a shaft 224 connecting the first idler 32 a to the cage220. The cage 220 may include a plurality of slots 222. Each of theplurality of slots 222 may accept a respective planetary gear shaft suchthat rotation of the one or more planetary gears rotates the cage 220and the first idler 32 a. The shafts of the planetary gears may berotatably captured within the slots 222, such that the shafts of theplanetary gears cause the cage 220, the first idler 32 a, and the rollertube 18 to rotate about the longitudinal axis 12 as the shafts of theplanetary gears rotate about the longitudinal axis 12.

FIGS. 2A-2D depict an example drive assembly 30. As shown in FIGS. 2Aand 2B, a drive assembly 30 may include a motor 34 having a drive shaft38 that is elongate along the longitudinal direction L. In accordancewith the illustrated orientation of the motorized window treatmentsystem 10, the longitudinal direction L extends parallel to alongitudinal axis 12 of the roller tube 18. The drive shaft 38 maydefine a drive shaft rotational axis 206. The drive shaft 38 may includea distal end 230 that is spaced from the motor 34. The distal end 230may be a first distance D1 from the motor 34. An intermediate gear 70may be a second distance D2 from the motor 34. The second distance D2may be longer than the first distance D1. The drive assembly 30 mayinclude a drive gear 42 that is attached (e.g., fixedly attached) to thedrive shaft 38 and may include a gear assembly 46. The gear assembly 46may be operatively coupled to (e.g., in communication with) the drivegear 42 and the roller tube 18 such that actuation of the motor 34transmits rotation of the drive shaft 38 through the gear assembly 46and to the roller tube 18. For example, the gear assembly 46 may beoperatively coupled to the drive gear 42 and the roller tube 18, suchthat actuation of the motor 34 causes the roller tube 18 to move thecovering material 22 between a first position (e.g., an open position)and a second position (e.g., a closed position). The drive assembly 30may be configured such that the motor 34 can operate at an efficientspeed while remaining below a noise threshold (e.g., maintainingsatisfactory decibel levels). For example, the drive assembly 30 may beconfigured so that the motor 34 can be operated at a more efficientspeed as compared to the known drive assemblies while a noise level ofthe motorized window treatment system remains below 33 dBa.

The drive gear 42 may include a coupling portion 50 and a toothedportion 54 that extends from the coupling portion 50 along thelongitudinal direction L. As shown in FIG. 2D, the coupling portion 50may define a channel 58 that is elongate along the longitudinaldirection L and is configured to receive the drive shaft 38 to therebyoperatively couple (e.g., couple) the drive gear 42 to the drive shaft38. The coupling portion 50 and the toothed portion 54 may be made of anon-metal material (e.g., a plastic material). The drive gear 42 may bemade of any material.

As shown in FIG. 2D, the drive gear 42 may be attached to the driveshaft 38, such that the toothed portion 54 is spaced from the distal end230 of the drive shaft 38. The toothed portion 54 may be spaced from themotor 34 (e.g., by approximately the second distance D2 along thelongitudinal direction L). The toothed portion 54 may be cantileveredwith respect to the drive shaft 38 along the longitudinal direction L.For example, the teeth of the toothed portion 54 may be supportedoutwardly from the drive shaft 38. As shown in FIG. 2D, the toothedportion 54 may be cantilevered with respect to the drive shaft 38, suchthat the toothed portion 54 is spaced from the drive shaft 38 along thelongitudinal direction L and does not overlap the drive shaft 38. Thedrive shaft 38 may define a drive shaft diameter Ds. The toothed portion54 may define a root diameter DR. The root diameter DR may be less thanor equal to the drive shaft diameter Ds. The drive gear 42 may define arotational axis in a coaxial relationship with the drive shaftrotational axis 206. When compared to a non-cantilevered drive gear, thesmaller or cantilevered drive gear 42 may move slower and may reducetransmitted vibrations and noise levels. A portion of the toothedportion 54 may overlap the drive shaft 38 such that a majority of thetoothed portion 54 is cantilevered with respect to the drive shaft 38.

The toothed portion 54 of the drive gear 42 may include between eightand twelve (e.g., eight or more and twelve or less) gear teeth 60. Asshown in FIGS. 2C and 2D, each gear tooth 60 may define a helical geartooth. The toothed portion 54 may have any number of gear teeth 60. Thegear teeth 60 may have any gear configurations (e.g., a gearconfiguration other than helical). For example, the toothed portion 54may have thirteen or more teeth and may define standard straight gearteeth.

As shown in FIGS. 2A-2C, the gear assembly 46 may be operatively coupledto (e.g., in meshed communication with) the toothed portion 54 of thedrive gear 42 and the roller tube 18 via the first idler 32 a, such thatactuation of the motor 34 transmits rotation of the drive shaft 38 tothe roller tube 18. As shown in FIG. 2C, the gear assembly 46 mayinclude a pair of intermediate gears 70 disposed on opposed sides of thetoothed portion 54 of the drive gear 42, a planetary gear set 74 that iscoupled to the roller tube 18 (e.g., via the first idler 32 a), and aconnecting gear 78 that is operatively coupled (e.g., in meshedcommunication with) both the (e.g., the pair of) intermediate gears 70and the planetary gear set 74.

The intermediate gears 70 may each include a first gear portion 82 and asecond gear portion 86 that extends from the first gear portion 82 alongthe longitudinal direction L. The first gear portions 82 may include aplurality of helical gear teeth 90 and the second gear portions 86 mayinclude a plurality of standard straight gear teeth 94. The gear teeth90 and the gear teeth 94 may have any gear configurations. As shown inFIG. 2C, the gear teeth 90 of the first gear portions 82 may mesh withthe helical gear teeth 60 of the drive gear 42, such that when the drivegear 42 is driven by the motor 34, rotation of the drive gear istransmitted to the intermediate gears 70.

The intermediate gears 70 may be disposed adjacent the drive gear 42.For example, as shown the intermediate gears 70 are disposed on opposedsides of the drive gear 42, such that the first gear portions 82 of theintermediate gears 70 are operatively coupled to the toothed portion 54of the drive gear 42, and such that respective axles 226 of theintermediate gears 70 are aligned with respect to each other along thetransverse direction T. Any forces acting on the toothed portion 54 byone of the pair of intermediate gears 70 may be offset by correspondingforces acting on the toothed portion 54 by the other of the pair ofintermediate gears 70. Each intermediate gear 70 may apply an equal andopposite force to the toothed portion 54 of the drive gear 42 so as toreduce the load on the cantilevered toothed portion 54 and reduce orotherwise prevent flexing of the toothed portion 54. A drive gear may beprone to flexing under the load of one intermediate gear. Flexing of thedrive gear may cause a whining noise. The corresponding (e.g., equal andopposite) forces from a pair of intermediate gears may reduce the noiseof the drive gear and gear assembly.

As shown in FIGS. 2B and 2C, the connecting gear 78 may include a firstgear portion 100 and a second gear portion 104 that is spaced from thefirst gear portion 100 along the longitudinal direction L. The firstgear portion 100 may include a plurality of standard straight gear teeth108 and the second gear portion 104 may include a plurality of standardstraight gear teeth 112. The gear teeth 108 and 112 may have any gearconfigurations. As shown in FIG. 2C, the gear teeth 108 of the firstgear portion 100 may mesh with the gear teeth 94 of the pair ofintermediate gears 70 such that when the pair of intermediate gears 70are driven by the drive gear 42, rotation of the pair of intermediategears 70 is transmitted to the connecting gear 78.

The planetary gear set 74 may include a ring gear 120 and a plurality ofplanetary gears 124 that are operatively coupled (e.g., in meshedcommunication with) the ring gear 120 and the second gear portion 104 ofthe connecting gear 78. The planetary gears 124 may be rotatably coupledto the first idler 32 a and may be disposed within the ring gear 120such that the planetary gears 124 and first idler 32 a together rotatearound the ring gear 120. For example, as shown, each planetary gear 124includes a shaft 228. The shaft 228 of each planetary gear 124 may bedisposed in a corresponding slot 222 of the cage 220. The shafts 228 ofthe planetary gears 124 may freely rotate in the slots 222, such thatthe shafts 228 are rotatably captive in the slots 222.

The ring gear 120 may include a plurality of internal gear teeth 128(see FIG. 1B) and each planetary gear 124 may include a plurality ofgear teeth 132 that mesh with the gear teeth 128 of the ring gear 120and with the gear teeth 112 of the second gear portion 104 of theconnecting gear 78 such that when the connecting gear 78 is driven bythe pair of intermediate gears 70, rotation of the connecting gear 78 istransmitted to the planetary gears 124. The planetary gears 124 and thefirst idler 32 a may rotate around the ring gear 120 in response torotation of the connecting gear 78. The second gear portion 104 may actas a sun gear to the planetary gears 124. The illustrated planetary gearset 74 includes three planetary gears 124 that are rotatably coupled tothe first idler 32 a. It should be appreciated that the planetary gearset 124 is not limited to three planetary gears 124, and that theplanetary gear set 74 may be alternatively configured to include anynumber of planetary gears 124.

The pair of intermediate gears 70, planetary gear set 74, and connectinggear 78 may be made from any material. For example, the pair ofintermediate gears 70, planetary gear set 74, and connecting gear 78 maybe made from a plastic material. The pair of intermediate gears 70,connecting gear 78, ring gear 120, and planetary gears 124 may includeany number of gear teeth, so long as the gears of the gear assembly meshtogether.

In use, actuation of the motor 34 may cause the drive gear 42 to rotate.Rotation of the drive gear 42 may be transferred through the gearassembly 46 and to the roller tube 18. The cantilevered toothed portion54 of the drive gear 42 may reduce the noise (e.g., decibel levels) ofthe drive assembly 30. Reducing the noise of the drive assembly 30 mayallow the motor 34 to be operated at a higher and/or more efficientspeed. Disposing the intermediate gears 70 on opposed sides of thetoothed portion 54 of the drive gear 42 may allow the intermediate gears70 to offset forces applied by the intermediate gears 70 to thecantilevered toothed portion 54 of the drive gear 42. For example, afirst one of the intermediate gears 70 may offset any forces transferredto the cantilevered toothed portion 54 by the other one of theintermediate gears 70. Offsetting any forces transferred may reducefatigue of the cantilevered toothed portion 54 and may allow the driveassembly 30 to be operated with a reduced (e.g., without) risk offailure. When the drive assembly 30 is quieter and/or operated at moreefficient speeds, less energy may be required to operate the motorizedwindow treatment system 10. When the drive assembly 30 is powered bybatteries, more efficient operation may prolong battery life.

FIG. 3 depicts an example drive gear 142 that may be implemented in themotorized window treatment 10 (e.g., in place of the drive gear 42). Asshown, the drive gear 142 may include a plastic toothed portion 154 anda coupling portion 150 having a non-plastic portion 152 and a plasticportion 151. The drive gear 142 may include a coupling portion 150 and atoothed portion 154 that extends from the coupling portion 150 along thelongitudinal direction L. As shown in FIG. 3, the coupling portion 150may define a channel 158 that is elongate along the longitudinaldirection L and may be configured to receive the drive shaft 38 tothereby couple the drive gear 142 to the drive shaft 38. The toothedportion 154 may be made of a plastic material. The coupling portion 150may include a plastic portion 151 and a non-plastic portion 152. Theplastic portion 151 may define the channel 158 and may couple the drivegear 142 to the drive shaft 38. The non-plastic portion 152 may be madeof rubber and may couple the toothed portion 154 to the plastic portion151. The plastic portion 151 may include a coupling member 153. Thenon-plastic portion 152 may be overmolded onto the coupling member 153to thereby couple the plastic portion 151 to the non-plastic portion152. As shown in FIG. 3, the non-plastic portion 152 may isolate thetoothed portion 154 from the drive shaft 38 to reduce the noise (e.g.,the decibel levels) of the drive assembly. The toothed portion 154 maybe attached to the non-plastic portion 152 using any known methods. Thenon-plastic portion 152 may be made of materials other than rubber.

The drive gear 142 may be coupled to the drive shaft 38 such that thetoothed portion 154 is cantilevered with respect to the drive shaft 38along the longitudinal direction L. As shown in FIG. 3, the entiretoothed portion 154 may be cantilevered with respect to the drive shaft38 such that the entire toothed portion 154 is spaced from the driveshaft 38 along the longitudinal direction L by at least the non-plasticportion 152 of the coupling portion 150. The drive shaft 38 may define adrive shaft diameter Ds. The toothed portion 154 may define a rootdiameter DR. The root diameter DR may be less than or equal to the driveshaft diameter Ds.

The toothed portion 154 of the drive gear 142 may include between eightand twelve (e.g., eight or more and twelve or less) gear teeth 160. Asshown in FIG. 3, each gear tooth 160 may define a helical gear tooth.The toothed portion 154 may have any number of gear teeth 160, and thegear teeth 160 may have any gear configurations. For example, thetoothed portion 154 may have thirteen or more teeth and may be standardstraight gear teeth.

1. A drive assembly comprising: a motor having a drive shaft thatdefines a drive shaft rotational axis, the drive shaft defining a distalend that is spaced from the motor, wherein the drive shaft defines adrive shaft diameter; a drive gear that engages the distal end of thedrive shaft, the drive gear having a toothed portion adapted to rotateabout the drive shaft rotational axis, wherein the toothed portion ofthe drive gear is spaced from the distal end of the drive shaft alongthe drive shaft rotational axis; and a gear assembly operatively coupledto the toothed portion of the drive gear such that actuation of themotor causes the drive gear to rotate the gear assembly.
 2. The driveassembly of claim 1, wherein the toothed portion of the drive geardefines a root diameter that is less than the drive shaft diameter, andwherein the toothed portion of the drive gear defines a channel thatreceives the distal end of the drive shaft.
 3. The drive assembly ofclaim 1, wherein the toothed portion comprises less than 12 gear teeth,and wherein the gear teeth are helical.
 4. The drive assembly of claim1, wherein the drive assembly is operatively coupled to a roller tubefor rotating the roller tube about a longitudinal axis defined by theroller tube.
 5. The drive assembly of claim 4, wherein the drive shaftextends parallel to the longitudinal axis of the roller tube.
 6. Thedrive assembly of claim 1, wherein the distal end of the drive shaft isspaced from the motor by a first distance and the toothed portion isspaced from the motor by a second distance that is greater than thefirst distance.
 7. The drive assembly of claim 1, wherein the toothedportion is comprised of plastic and the drive gear further comprises acoupling portion that extends from the toothed portion and mates withthe drive shaft so as to operatively couple the drive gear to the driveshaft, the coupling portion comprising a non-plastic portion thatoperatively couples the toothed portion to the coupling portion.
 8. Thedrive assembly of claim 1, wherein the gear assembly comprises a pair ofintermediate gears disposed on opposed sides of the toothed portion ofthe drive gear, a planetary gear set that is operatively coupled to theroller tube, and a connecting gear that is operatively coupled to thepair of intermediate gears.
 9. The drive assembly of claim 8, whereinthe gear assembly further comprises a cage that rotatably captures oneor more shafts of the planetary gear set such that rotation of theplanetary gear set causes the cage to rotate, and wherein the cage isconnected to the roller tube via an idler such that rotation of the cagecauses the roller tube to rotate about the longitudinal axis.
 10. Thedrive assembly of claim 1, wherein the gear assembly is operably coupledto the roller tube such that actuation of the motor causes the rollertube to rotate about the longitudinal axis.
 11. A motorized windowtreatment system comprising: an elongate roller tube defining alongitudinal axis; a covering material windingly attached to the rollertube; a drive assembly that is operatively coupled to the roller tubefor rotating the roller tube about the longitudinal axis, the driveassembly including: a motor having a drive shaft that defines a driveshaft rotational axis, the drive shaft defining a distal end that isspaced from the motor, wherein the drive shaft defines a drive shaftdiameter; a drive gear that engages the distal end of the drive shaft,the drive gear having a toothed portion adapted to rotate about thedrive shaft rotational axis, wherein the toothed portion of the drivegear is spaced from the distal end of the drive shaft along the driveshaft rotational axis; and a gear assembly operatively coupled to thetoothed portion of the drive gear such that actuation of the motorcauses the gear assembly to rotate.
 12. The motorized window treatmentsystem of claim 11, wherein the toothed portion defines a root diameterthat is less than the drive shaft diameter.
 13. The motorized windowtreatment system of claim 11, wherein the toothed portion of the drivegear comprises a plurality of gear teeth that are helical gear teeth.14. The motorized window treatment system of claim 11, wherein thedistal end of the drive shaft that is spaced a first distance from themotor, and wherein the toothed portion of the drive gear is spaced asecond distance from the motor, and wherein the second distance isgreater than the first distance.
 15. The motorized window treatmentsystem of claim 11, wherein the drive gear is cantilevered with respectto the distal end of the drive shaft, and wherein the drive gear definesa channel that receives a portion of the drive shaft.
 16. The motorizedwindow treatment system of claim 11, wherein the drive gear furthercomprises a coupling portion that extends from the toothed portion andmates with the drive shaft so as to operatively couple the drive gear tothe drive shaft, the coupling portion comprising a non-plastic portionthat operatively couples the toothed portion to the coupling portion.17. The motorized window treatment system of claim 11, wherein the gearassembly is configured to be operatively coupled to the roller tube suchthat actuation of the motor causes the roller tube to move the coveringmaterial between an open position and a closed position.
 18. Themotorized window treatment system of claim 11, wherein the coveringmaterial is a screen.
 19. The motorized window treatment system of claim11, wherein the gear assembly comprises a pair of intermediate gearsdisposed on opposed sides of the toothed portion of the drive gear, aplanetary gear set that is operatively coupled to the roller tube, and aconnecting gear that is operatively coupled to the pair of intermediategears.
 20. The motorized window treatment system of claim 19, whereinthe gear assembly further comprises a cage that rotatably captures oneor more shafts of the planetary gear set such that rotation of theplanetary gear set causes the cage to rotate, and wherein the cage isconnected to the roller tube via an idler such that rotation of the cagecauses the roller tube to rotate about the longitudinal axis.